Auxiliary drill collar connection



1965 J. H. PANGBURN ETAL 3,203,713

AUXILIARY DRILL COLLAR CONNECTION Filed May 3. 1962 JAMES H. PANGBURNCLAY TRIGG INVENTORS AGENT FIG.|

United States Patent Office 3293,2 13 Patented Aug. 31, 1965 3 203,713AUXILIARY Dani COLLAR CONNECTION James H. Pangburn and Clay Trigg, bothof R0. Box 4364, Oklahoma City 9, Okla. Filed May 3, 1962, Ser. No.192,103 1 Claim. (Cl. 285-18) The present invention relates to Welldrilling and more particularly to drill collars.

In drilling oil wells it is conventional to use a plurality ofrelatively heavy tubular sections, commonly referred to as drillcollars, on the depending end portion of a rotary drilling string toprovide sufficient mass or weight for forcing the drill bit into theformation being drilled. Since the drilling operation is formed byrotation of the drill string and a certain amount of lateral bendingforces are applied to the drill string, the drill collars have atendency to crystallize and break off the pin or box end portion. Thisusually results in an expensive and timeconsuming fishing job.

It is, therefore, the principal object of the instant invention toprovide an auxiliary means for connecting adjacent ends of drill collarsso that they may be pulled from the drilled hole in the event of a pinor box break.

Another object is to provide a device of this class which does nothamper the circulation of drilling fluid through the drill collars.

An additional object is to provide a device of this class which may bedisconnected from the next lower drill collar when a pin or box hasbroken while the drill string is in the hole.

Still another object is to provide a slip joint type connection fordrill collars which is fluidtight.

The present invention accomplishes these and other objects by connectinga tubular member to the wall forming the bore in the depending end ofone drill collar and slidably connecting the other end of the tubularmember to the wall forming the bore of the upper end portion of the nextlower drill collar.

Other objects will be apparent from the following description when takenin conjunction with the accompanying single sheet of drawings, wherein:

FIGURE 1 is a fragmentary vertical cross-sectional view of the deviceconnected with the adjacent ends of driil collars and illustrating, bydotted lines, the relative position of the components during normaloperation; and

FIGURE 2 is a fragmentary elevational view of the depending end portionof the device.

Like characters of reference designate like parts in those fi 'ures ofthe drawings in which they occur.

In the drawings:

The reference numeral indicates the device, as a whole, connected with apair of drill collars 12 and 14. The drill collars are conventionalhaving an externally threaded pin 16 formed on the depending end of theupper drill collar 12 and a cooperating internally threaded box end 18on the lower drill collar 14.

In carrying out the invention, the bore 20 of the drill collar 12 isenlarged or counterbored a selected diameter and depth from the pin end,as at 22. The inward end of the wall, forming the counterbore 22,threadedly engages the upper end portion of an elongated tubular memberormandrel 24 freely received within the counterbore 22 and having a bore26 diametrically equal with respect to the bore 29 of the drill collar12.

The upper or box end portion of the drill collar 14 is similarlycounterbored, inwardly of the threads 18, as at 28, a selected depth forslidably receiving a circumferentially enlarged flange portion 30 of thedepending end portion of the tubular member 24. The length of theconnector or tube 24 is determined by the spacing desired be tween thepin and box ends before connecting the latter to facilitate the use ofwrenches in assembly and removal of the unit it). The depth of thecounterbore 28 is such that the depending end surface of the tube 24remains in spaced relation with respect to the inward end of thecounterbore 28, not shown, when the pin and box are connected. The drillcollar 14 is further counterbored a selected depth, adjacent the inwardend of the thread-s 18, as at 32, forming an annular shoulder 34. Thecounterbore 28 is internally left-hand threaded adjacent the shoulder 34for threadedly receiving a sleeve 36 having a bore 38 slidably receivingthe periphery of the tubular member 24 above the flange 30. The sleeve36 is provided with an outstanding annular flange 4t], closely receivedby the counterbore 32 and which seats against the shoulder 34. The innerwall of the sleeve 36 is provided with a plurality of packing or O-rings42 to seal fluidtight with the periphery of the tube 24. The upper edgesurface of the tube flanged portion 30 is beveled inwardly forcooperative engagement with a similar bevel formed on the depending edgesurface of the sleeve 36, as at 44. The upper edge surface of the flange30 and depending edge surface of the sleeve 36 are further formed byinclined surfaces 46 and perpendicular surfaces 48 to define acircumferential series of cooperating ratchet teeth for the purposesmore fully explained hereinbelow.

Operation In operation, the device is assembled as describedhereinabove. In the event the pin or the box of a drill collar breaks,the upper portion of the string may be lifted thus engaging the flange30 with the depending end of the sleeve 36 to lift the entire stringfrom the well. If, however, the drill bit is stuck or it is desired topart the string at a drill broken collar for washing over the portion ofthe string remaining in the hole, the ratchet teeth on the flange 30 isengaged with the ratchet teeth on the depending end of the sleeve 36 andthe drill string is rotated in the conventional clockwise directionwherein the respective ratchet teeth act to unscrew the sleeve 36 fromthe drill collar 14.

Obviously the invention is susceptible to some change or alterationwithout defeating its practicability, and we therefore do not wish to beconfined to the preferred embodiment shown in the drawings and describedherein, further than we are limited by the scope of the appended claim.

We claim:

An auxiliary drill collar connector for connecting the adjacent ends ofan upper drill collar to a lower drill collar, said drill collars havingcooperatingly threaded box and pin ends and having connterboresextending coaxially inward beyond the threads of their threadedlyconnected ends, comprising: an elongated tubular member threadedlyconnected coaxially at one end to the wall forming the inward endportion of the counterbore in said upper drill collar, the depending endportion of said tubular member having an annular outstanding flangeslidably received coaxially by the counterbore in said loWer drillcollar; means sealing the depending end portion of said tubular memberfiuidtight within the lowermost drill collar, said means comprising arelatively short sleeve of a size complementary slidably surroundingsaid tubular member and threadedly connected to the Wall forming thecounterbore in said lower drill collar inward- 1y of the threads of thelatter and above the flanged end on said tubular member, said sleevehaving at least one annular packing ring groove formed in its innerperiphery, and a packing ring within the groove of said sleeve; andcooperating ratchet teeth formed on the upper edge surface of theflanged end of said tubular member and the depending end surface of saidsleeve, said ratchet teeth being engaged with each other by an expandedtelescoped position of said tubular member with respect to 4 saidsleeve, whereby reverse rotation of said upper drill collar unscreWssaid tubular member from said upper drill collar.

References Cited by the Examiner UNITED STATES PATENTS 338,783 3/86Ritchie 285-302 X 1,796,611 3/31 Montgomery 285-655 2,180,795 11/39Christensen 285-4102 X 2,481,404 9/49 Donner 285-356 2,851,252 9/58 LeBus 285-302 FOREIGN PATENTS 10,570 1903 Great Britain. 867,989 5/61Great Britain.

CARL W. TOMLIN, Primary Examiner.

